


Somethings not right

by Multi_In_The_Deep



Category: UTAU, Undertail - Fandom
Genre: Fetish, M/M, Sex, dont read if you’re not into it, egg pregnancy
Language: English
Status: Completed
Published: 2019-07-11
Updated: 2019-07-11
Packaged: 2020-06-26 07:32:40
Rating: Mature
Warnings: Creator Chose Not To Use Archive Warnings
Chapters: 2
Words: 2,613
Publisher: archiveofourown.org
Story URL: https://archiveofourown.org/works/19763485
Author URL: https://archiveofourown.org/users/Multi_In_The_Deep/pseuds/Multi_In_The_Deep
Summary: The last thing he wanted to do was pull out. His mind flashing an image of blue with the fullest belly yet. THAT was what he would aim for. And he will achieve it.





	1. Chapter 1

**Author's Note:**

  * Inspired by [A little Eggstra](https://archiveofourown.org/works/14152086) by [rehliamonster](https://archiveofourown.org/users/rehliamonster/pseuds/rehliamonster). 



Blue and sans laid on the couch of their new house, thanks to some problems that occurred in blues au he and his brother had evacuated the destroyed universe to sans’, and as a year went by the two begun to get to know each-other more, their first kiss was under the mistletoe their first Christmas. It had been a private party just them, Papyrus, Cheeto and undyne. 

That year seemed to have gone fast, the both of them both becoming more and more shy with each-other until blue had finally gathered the confidence to make the first move, to ask sans about feelings. That was a night they had spent together in waterfall, sitting on a bench starring up at the phospherant mushrooms. They walked home that night with their hands together and their fingers twined. 

Blue had worked hard since then, becoming a pretty well known fully fledged guard and working above pap with a smile, their sparring matches with undyne shook the earth more then paps did, but blue was berry controlling of his attacks, it was harder to make him accidentally miss his target then to actually hit him. 

By about half way through that year a human had fallen, and even though blue was to capture them, he couldn’t, instead him and sans escorted the small human in the striped sweater right to the castle, where they had broken the barrier themselves with no interuptions, a much more peaceful outcome then what sans was scared of.

It took another two months for humans to accept the monsters, and in that time sans and blue had become closer, almost never leaving each others sides, sharing a tent and giving each-other pecks on the cheek, sometimes they would even kiss pationately so long as it wasn’t public.

Finally when it reached autumn the monsters were allowed to live in houses, and the two small skeletons were given their own house to move into on their own. The royal guard had broke up and now blue worked a cop job alongside undyne and some humans. Sans worked at a pizza place as a delivery man on a small delivery scooter. 

As Christmas came closer the two had become more cuddly however, snuggled up on the couch with a blanket or two watching mettaton dance around on screen with a female singer, the two had become close recently, collaborating on some of their greatest songs. Each one rising blues spirits enough for a little fun the both had together in the bedroom. 

However, recently blue had begun sounding a lot more vocal when sans hammered into him. It had been putting a heat into sans’ stomach and cock that he wasn’t too sure about. So they had tried dropping it. However recently that seemed to be weighing on their minds, blue looking at his stomach as if it was pathetic, looking up at sans with large eyes for a few moments, before away again “please?” He whined quietly. Catching sans just barely off guard, he knew exactly what “please” had meant. 

Please just fill me, fuck me till I’m absolutely full of magic, until I look like the human women who carry their children in their swollen middles on the street.

But please had to be ignored, or did it? Those large blue eyes were looking at sans so longingly it was hard to shake his head at the younger of the two, his mouth beginning to water as blue leaned closer “please”he repeated, seeming to look that bit less relaxed now. 

It took all sans’ will power to look away, but that didn’t help, the upset moan like noise that blue made just made sans want it more, He fidgeted a moment before slowly getting up, picking up the smaller as he jogged up the stairs, his eye-sockets closed ‘just a quick fling, that can’t hurt’ he told himself. ‘It can’t hurt’.

The two got onto the bed quick, blue blushing slightly as he took his new long pants off and shoved them under the bed, he looked at sans a moment before smiling “I wanna try something new Sansy!” Blue cooed happily, his round cheeks dusting his bright blue magic, sans looked over blues body, his thighs and dripping pussy already summoned for him, making him grin as he took his own pants off, humming “Sure, get on the bed but on your hands and knees” sans instructed, his stomach squeezing slightly at the idea of his adorable little berry on his hands and knees waiting for him, his member perking up at the idea making him blush. His shy blush 

He looked towards blue when he took his pants off. The smaller skeleton on his knees propped up on his elbows, exposing his hindquarters to sans. This made sans want to jump right away, to slam into blue and hear the smaller whimper, but there was another desire within him. A desire he didn’t understand yet, his insides warming again as he slowly climbed up onto the bed, gently leaning over blue, lining up with the others entrance as he slipped a hand up the others sweater, feeling over their magic, coating over each bone, tracing around what seemed to be a nipple as blue gasped, sans smiled as he begun to push in, purring as he felt the warmth of his mates insides, no matter how ready blue would be he would always end up gasping, or whining. 

The perfect noises for sans to get in the mood. 

He smiled as he leaned further over blue, beginning to lick against the others spine as his hand moved further down to blues stomach, when they had first met blue made an effort to keep his magic to attacks, but the more they knew each-other the more blue seemed to slip between this, going on diets only to ruin them from a cookie each once in a while, he wasn’t ‘fat’ per say, more adorably chubby, his belly round enough to play with during their sessions. 

This time however, when sans touched it, he felt his cock twitch, his body shivering for a moment at the sensation, he couldn’t possibly be close already. 

But blue below him? They seemed to take great pleasure in the feeling, his own insides fluttering as his bluntly classed fingers dug into the sheets, but never tore through. Sanses mind was rAcing in the slightest of panic, they both were close already, this wasn’t right. 

But at the same time, he felt a part of him numb, his mind clouding with the most leaned of faces blue had made in their sessions, driving him forward as blues moans grew louder beneath him.

The last thing he wanted to do was pull out. His mind flashing an image of blue with the fullest belly yet. THAT was what he would aim for. And he will achieve it. 

Blue let out a cry of pleasure, his insides coating in a warm fluid as he continued to claw the bed, sans purred against the other, speeding up more as he pressed his upper half closer to the other, nipping on the other skeletons collarbone as the both of them panted. Blue from his orgasm and sans from a strange build up in his member. Feeling both pleasured and worried once more, until he finally came, slamming his member all the way into blue as he filled the other up, moaning shakily as he gently leaned against the other, his hands feeling over blues belly as it bloated that tiniest bit, he smiled as he gently licked the others neck, causing blue to shiver and shift a little, he tried to make sans continue moving, but they stopped immediately, shivering. 

Sans froze, trying to move a little himself. 

No budging. He was stuck in blue, who seemed in a bit of pain each time he even moved, he looked at blue a moment before shuddering “this is….” He started, before trailing off. Blue shuddered a moment before gently resting his skull on his hands “I think you’re still emptying, your- hhh- your ding a ling feels so big sansy” he said. Sans blushed slightly at the idea, his head spinning with more lewed faces of blues as he felt his cock twitch again, and a sudden feeling of pressure at the base of his cock, he moaned quietly, shuddering “fuck-“ he swore, getting blues slightly upset face in return, but that face faltered at sanses next words   
“I don’t think I’ve even started blue.”


	2. What’s so bad about one egg?

**Summary for the Chapter:**

> something just wasn’t the same about sans right now. He was being so much more touchy then the sans he normally did it with. 
> 
> And that wasn’t even brushing on the topic of what sans was definitely doing to him right now.

Blues eyes widened, his body suddenly tense against sanses cock, witch now he could feel was definitely larger then normal. He felt blues stomach for a few moments before blue whimpered “what. Is. THAT” said, the building feeling begun to move down his cock, whatever it was it was making sans purr, his body relaxing against blue as he moaned “dunno” he said. 

Blue squirmed a little as the bulge in sanses cock pushed into his entrance, he continued to fidget even after whatever it was passed though, sitting at the top of sanses cock, the skeleton above him moaning again as he moved again “whatever it is, I think it goes in you” he said, moaning as blue felt the large bulge suddenly drop out of sanses member, the smaller ones eyes widened as he fidgeted more “that’s an EGG sans!! Get it out!” Blue squeaked, trying to pull away again only to whimper, sans pulled him closer again “dunno” he said once more, purring as another begun to push its way down his cock “skeletons don’t lay eggs blue” 

Blue felt frustrated at his mate right now as what was definitely an egg buried itself in his womb wall, these bulge in sanses cock were a fist-size each, and he had no idea how many there would be. The first egg already making a bit of a bulge in what used to be purely magic, and the pain of another making its way through sans’ cocktail and against blues entrance announced itself again. Along with sanses hand on blues stomach, gently prodding his fingers into blues magic flesh, something just wasn’t the same about sans right now. He was being so much more touchy then the sans he normally did it with. 

And that wasn’t even brushing on the topic of what sans was definitely doing to him right now. 

Sans’ member pushed a second out and it made itself comfortable in blues walls, his belly pushing out more now, he looked like he was about half way through a normal human pregnancy already, his stomach feeling stretched out and tight. It had been a while since he had sanses magic in him, but his stomach this time was filled with small, solid objects that made his stomach feel heavy, they made his belly poke out so much more and made him feel so bloated. 

But that wasn’t gonna be all of it, a third egg begun to announce itself against blues entrance, making blue whimper softly, sans moved to nuzzle his neck again, gently pressing his hands against blues swollen middle “you wanted a clutch a few weeks ago, hmm?” Sans babbled, now that he had mentioned it blue did remember saying that, but never once had he thought sans would LAY EGGS in him. The other gently pressed on his stomach. Making blue throw back his head in a moan, making sans laugh “we’ll have a clutch blue, a cute clutch of adorable chubby cheeked skeletons” he said, blue, however felt a bit wary, sans was the nervous one about having kids, wasn’t he?

The third egg dropped into blues womb, his stomach stretching out further with the three warm eggs amongst both skeletons liquids inside blues belly, round enough that he looked half way through his seventh month. He shuddered as he felt his stomach, letting out another shaky moan as sans begun to give him another one. It was starting to make blue feel dizzy thinking about all the children inside him. He felt his belly before whimpering again “sans, it’s getting too tight” he whined, sans gave him a soft kiss, purring as he moved in right up against blue “one more babe” he said, feeling blues belly once more “I can feel it” he said, grinning. Blue shuddered as he begun to shiver “it’s coldI don’t like it” he said whilst shivering, putting his head between his arms, only to feel the egg begin to slide down into him quicker, sighing as he stayed at that angle, yes it was painful to keep himself off the bed, and yes he was beginning to feel tired. 

But no. He wasn’t giving up yet. Not when he was just getting used to sans’ fucking again, even if it was so different and wired that he didn’t know how to feel about it, finally the last egg dropped in, making him officially look full term. He cried out in discomfort as he moved a little, sans purred as he begun to pull out, then back in, blue gasped as he pressed a hand to his swollen middle “SANS!” He squealed “what are you doing!?” 

Sans laughed as he pushed all the way back in and begun pulling out once more, he was going slow enough for it to feel good right now to blue, but the eggs moved with every little movement, causing his stomach to feel heavier then it was “I hear you cum again after this, it makes the mate feel better” he said, grinning. Blue looked at the others wispy white eye-lights, before sighing “can I just… r-roll over please?” He asked softly. Not really expecting a yes but asking anyways. 

Sans however didn’t seem to hear him, speeding up just enough that he was shaking blue, and to an extension, the eggs. “Sans” he moaned “stop being so rough!” He whined, his claws tearing through the sheets for the first time ever as he felt sudden pressure begun to build up in the underside of his stomach, he moaned loudly for a moment before his stomach grew even tighter, both him and sans emptying at once, causing his belly button to slowly pop, he whimpered as he felt it again, when he had felt his belly button though, his eye-lights shrank. Quickly pulling out and laying on his side, shuddering as he felt his cramped stomach, shuddering as he looked to sans “I’m not gonna fit into any of my clothes anymore sans” he mumbled as sans grinned “we’ll manage, I’d be more worried about how many of those eggs are slugs and witch aren’t” he said, purring. Blue sighed, leaning back against the pillow. 

Yes, he was gonna have kids, but he wasn’t even a day in and he was huge and uncomfortable, would his long pants even fit so snugly anymore? He wondered, slowly struggling to sit up, whimpering and hissing as he got up. As sans moved to help him he glared at the other “don’t touch” he said, frowning “it doesn’t feel right” he mumbled, looking away as he slipped into the floor and peeked under the bed for his pants, only to notice they were gone, looking up at sans before back under the bed, sans laughed as he got off the bed on the opposite side “case of the pregnancy brain already babe? You put them in on this side” sans said, chuckling, blue let out an agitated sigh, one Because he hated being proven wrong, and two Because he was too front heavy and bloated to get up.


End file.
